Relay



P. MACGAHAN.

RELAY.

APPLICATION HLED use. 14, 1916.

1 ,42 1 ,272 Patented June 27, 1922.

WITNESSES: INVENTOR Q Paul MscGa/ran.

I. i AT1"ORNEY UNITED STATES PATENT OFFICE.

4 1; MAcGAI-IAN, or PITTSBURGH, PENNSYLVANIA, ASSIGNOR "lO wns'r nenousn Errors-1c AND anuracronrne contrary, a, conronn'rroiv or rnnnsynvema.

RELAY.

Specification of Letters Patent. PgtfielltQd J Application filed December 14, 1916. Serial No. 136,887.

ularly to means for protecting the contact members and the control springs thereof.

One object of my invention is to provide means whereby the contact members of a relay are precluded from becoming. disengaged under predetermined conditions.

Another object of my invention is to provide means or" the above indicated character that shall be adapted to quickly establish a closed-circuit connection across the conductcontrol spring and the contact members of the. relay, when the contact members are engaged, to preclude the full trip-coil current from traversing and, consequently, overheating the control spring.

In the carrying :out of my invention, I provide a relay for controlling the tripping of a circuit interrupterand an electro magnetic devlce that is adapted to be energized. when the contact members 01' the relay are engaged to co-operate with the armature of the relay to maintain the .contact members in engagement and to quickly establish a closedecircuit connection. thereu across until the circuit interrupter isopened.

. the relay to bearly close, an arc will not be drawn because. the contact members cannot Qfilly connect the movable contact Thus, if only, sufficient overload traverses the C1IC11l13130 cause the contact members of become disengaged so long as the circuit interrupter remains closed. The electromagnetic device is adapted to quickly establish the closed-circuit connection around the control spring of the relay for the purpose of Fig. 1 of the drawings, an electrical i cuit 1 is Pro ded h. a circuit int r rupter 2 having a trip coil 3 that is adapted to be. controlled by a relay 4 in accordance with the current traversing the circuit 1.

The relay 1 comprises a magnetizable core member .5' and a main current winding 6 that is operatively connected to the secondary winding 7 of a series transformer S, the primary winding 9 of which is connected in series with one conductor of the. circuit 1. An armature 10 is mounted on a shaft 11 and is. adapted to be turned when current f a p eterm ned va ue t ver e he Winding .6, The armature 10 may be delayed or not in its operation, as desired. A control spring 12 is secured at one of its ends, to a movable contact member 13 on the armature 10 and, at its other end, to a stationary member 14. The movable contact member 13 is adapted to engagea stationary contact member 15 under predetermined conditions for the purpose of completing a circuit through the winding 16 of an electromagnet 17, a control switch 18 on the, circuit interrupter 2,

the trip coil 3 and a source 19 of electromotiveforce. A magnetizable member 20 is, mounted on the armature. 10 and; is adapted to be quickly attracted by the electrolllagnet 17 when'the winding 16 is energized for the purpose of holding the contact members 13 and 15 in effective engagement and for causing the contact member 18 to engage an auxiliary stationary contact member 21. Thatis, the attraction between the magnetizable member 20 and the electromagnet 1:7 is caused to quickly establish closed-circuit connection 22 around the contact members of the relay 4 and the spring 12 before the current that traverses f the trip coil rises to a relatively high value.

WYhen an. overload. of a predetermined value traverses the circuit 1, the armature 10 will turn to effect engagement between the contact members 13, 1 5 and 21, thereby energizing thev trip coil 3 to cause the in terrupterQ to open. However, when the interrupter Z: opens, the switch 18 is actuated to open the circuit of the winding lfi, thereby permitting the spring '12 to turn the armature 10 to its initial position. It will be understood that, so long as the in terrupter 2 remains closed, the contact members will not beadisengaged and the circuit of the trip. coil 3 willalways be interrupted at the control switch 18. Thus, the contact me i 3; an 15 wi not be p tted o burned and the spring 12 will not be overheated by reason of the full trip-coil current traversing the same.

In Fig. 2 of the drawings, the armature 1O provided with a notch 23 on its periphery that is adapted to be engaged by a similarly shaped magnetizable member 24, when the electromagnetic device 25 is energized, to cause the armature 10 to be quickly turned a sufficient distance to cause its contact member 13 to be held in engagement with the stationary contact members 15 and 21. In other respects, the device shown in Fig. 2 is similar to the device shown in Fig. 1. That is, the contact members 13 and 15 are quickly moved into engagement and held in that position until the operation of the circuit interrupter 2 causes the switch 18 to open the circuit of the trip coil 3.

I do not limit my invention to the particular devices illustrated, as it may be variously modified without departing from the spirit and scope of the invention as set forth in the appended claims.

I claim as my invention:

1. The combination with a circuit interrupter, a trip coil therefor and a relay having an armature and contact members for controlling the energization of the trip coil and employing a control spring for controlling the armature and for electrically connecting one contact member to a control circuit, of an electromagnet adapted to be energized when the relay operates to maintain the contact members in engagement and to effect the completion of an auxiliary circuit to shunt the control spring.

2. The combination with a circuit interrupter, a trip coil therefor and a relay having an armature and contact members for controlling the energization of the trip coil and employing a control spring for controlling the armature and for electrically connecting one contact member to a control circuit, of an electromagnet adapted to be energized when the relay operates to maintain the contact members in engagement, and means controlled by the electromagnet for completing a circuit in shunt relation with respect to the control spring to divert the greater portion of the tripping current therefrom.

3. The combination with a circuit interrupter, a trip coil therefor and a relay having an armature and contact members for controlling the energization of the trip coil and employing a control spring for controlling the armature and for electrically connecting one contact member to a control circuit, of means energized upon the operation of the relay for shunting the control spring to preclude the normal value of tripping current from traversing the same.

4-. The combination with a circuit interrupter, a trip coil therefor and a relay having an armature and contact members for controlling the energization of the trip coil and employing a control spring for controlling the armature and for electrically connecting one contact member to a control circuit, of means energized upon the operation of the relay to maintain the contact mem bers in engagement and to effect the completion of an auxiliary circuit to shunt the control spring to divert the greater portion of the tripping current therefrom.

5. The combination with an inductiontype relay embodying a movable armature, a plurality of main contact members, engagement of which is controlled thereby and a control spring for controlling the movement of the armature and for electrically connecting one contact member to a control circuit, of means for close-circuiting the control spring immediately upon the engagement of the main contact members.

6. The combination with an inductiontype relay embodying a movable armature, a plurality of main contact members, engagement of which is controlled thereby and a control spring for controlling the movement of the armature and for electrically connecting one contact member to a control circuit, of an electromagnet energized upon the engagement of the main contact members for maintaining the same in effective engagement and for effecting the completion of a closed circuit around the control spring to preclude an excessive value of current from traversing the same.

7. The combination with a circuit interrupter, a trip coil therefor, and a relay having an armature, a plurality of contact members, engagement of which is controlled by the armature for controlling the energization of the trip coil, and a control spring for electrically connecting one contact memher to a control circuit. of an electromagnet adapted to be energized by the tripping current, when the relay effects engagement of the contact members. to maintain the contact members in effective engagement and to effect the completion of a closed circuit around the control spring to preclude an excessive value of tripping current from traversing the same, and means controlled by the interrupter for opening the circuit of the trip coil.

8. The combination with a circuit interrupter, a trip coil therefor and a relay having a movable armature, a contact member controlled thereby to control the energization of the trip coil and a control spring for controlling the armature and for connecting the contact member to a control circuit, of an electromagnet that is energized, when the relay operates to energize the trip coil, to cooperate with the armature to maintain the contact member in a predetermined position and to quickly effect the establishment of a closed circuit around the control spring to preclude an excessive value of tripping current form traversing the spring and to maintain the trip coil in its energized condition.

9. The combination with a circuit inter rupter,a trip coil therefor and a relay having a movable armature, a contact member controlled thereby to control the energization of the trip coil and a control spring for controlling the armature and for connectinothe contact member to a control circuit, 0' an electromagnet that is energized, when the relay operates to energize the trip coil, to

cooperate with the armature to maintain the contact member in a predetermined position and to quickly effect the establishment of a closed circuit around the control spring to preclude an excessive value of tripping current from traversing the spring and to maintain the trip coil in its energized condition,

and means controlled independently of the relay for rendering the electromagnet inoperative.

In testimony whereof, I have hereunto subscribed my name this 23rd day of November 1916.

PAUL MAOGAHAN. 

